Electronic
pressure measurement
Dual differential pressure transmitter
Model A2G-52, with Modbus interface
WIKA data sheet SP 69.09
Applications
■■ Dual differential pressure transmitter for monitoring air,
non-inflammable and non-aggressive gases
■■ Fan, blower and filter monitoring
■■ Pressure and flow monitoring
■■ Monitoring and control of valves and air shutters
■■ Pressure monitoring in clean rooms
Special features
■■ Simple mounting
■■ Two differential pressure sensors in one instrument
■■ Two inputs for temperature sensors or analogue signal
■■ With Modbus interface
■■ Reliable and cost-effective
Dual differential pressure transmitter, model A2G-52
Description
The model A2G-52 dual differential pressure transmitter
combines two differential pressure transmitters in one
instrument, so that pressure can be measured from two
different control points.
The model A2G-52 has a Modbus interface and an input
interface. When using the input interface, temperature
transmitters can be saved by directly connecting temperature
sensors. As a result, costs can be reduced considerably.
WIKA data sheet SP 69.09 ∙ 04/2015
Page 1 of 4
Description
Standard version
Design
■■ EMC directive 2004/108/EC
■■ RoHS directive 2002/95/EC
Process connection
Connecting nozzle (copper alloy), lower mount, for hoses
with inner diameter 4 mm
Accuracy (total pressure)
±1.5 % +1 Pa
(including general accuracy, temperature drift, linearity,
hysteresis, long-term stability and repeat accuracy)
Case
Plastic (ABS), cover PC
Measuring element
Piezo measuring cell
Measuring ranges
-250 … 2,500 Pa and -250 … 7,000 Pa
Units of measure selectable on the display in the menu (Pa,
mbar, inch WC, mm WC, psi)
LCD display
2-line display (12 characters/line)
Line 1: Active measurement, inlet A
Line 2: Active measurement, inlet B
Response time
1 … 20 s selectable via menu
Electrical connection
Cable gland M20
2 x 4 spring-clip terminals, max. 1.5 mm2
Maximum pressure
400 kPa
Permissible temperature
Operation: -10 … +50 °C
Storage: -20 ... +70 °C
Humidity: 0 to 95 % rH
Ingress protection
IP 54 per EN 60529 / lEC 60529
Weight
150 g
Communication
Protocol:
Modbus via serial interface
Transfer mode: RTU
Interface:
RS-485
Byte format (11 bit):
Coding system: 8-bit binary
Bits per byte:
1 start bit, 8 data bits (the lowest data bit first), 1 parity bit,
1 stop bit
Baud rate:
Selectable in the menu
Address range: 1 ... 247 selectable in the menu
Page 2 of 4
Output signal
Modbus
Power supply
AC 24 V or DC 24 V ±10 %
Standard accessories
2 mounting screws
Options
■■ 4 duct connectors
■■ 2 x 2 m PVC hose, inner diameter 4 mm
Connection diagram
Power supply
AC 24 V / DC 24 V
A
Input 1
B
GND
24 V
Input 2
GND
GND
Dimensions in mm
WIKA data sheet SP 69.09 ∙ 04/2015
Zero point adjustment
■■ Manual push button
■■ With Modbus function code
Response time: 0.8, 2 or 10 s selectable in the menu
1. Remove both hoses from the pressure connections
⊕ and ⊖.
2. Press the SELECT button briefly (marked in red).
3. Wait until the LED turns off.
4. Reconnect the ⊕ and ⊖ hoses.
5. In normal operation, carry out a zero adjustment
every 12 months.
Modbus register
FC04 - Read input register
Register
Parameter description
Data type
Value
Display
3x0001
Program version
16 bit
0 ... 1,000
0.00 ... 99.00
3x0003
Pressure measurement A
16 bit
-250 ... 2,500
-250 ... 2,500 (Pa)
3x0002
3x0004
3x0005
3x0006
3x0007
3x0008
3x0009
3x0010
3x0011
3x0012
3x0013
Pressure measurement A
Input 1: 0 ... 10 V
Input 1: Pt1000
Input 1: Ni1000
Input 1: Ni1000-LG
Input 1: NTC10k
Input 2: 0 ... 10 V
Input 2: Pt1000
Input 2: Ni1000
Input 2: Ni1000-L
Input 2: NTC10k
16 bit
16 bit
16 bit
16 bit
16 bit
16 bit
16 bit
16 bit
16 bit
16 bit
16 bit
-250 ... 2,500
0 ... 1,000
500 ... 500
-500 ... 500
-500 ... 500
-500 ... 500
0 ... 1,000
-500 ... 500
-500 ... 500
-500 ... 500
-500 ... 500
-250 ... 2,500 (Pa)
0 ... 100 %
-50 ... +50 °C
-50 ... +50 °C
-50 ... +50 °C
-50 ... +50 °C
0 ... 100 %
-50 ... +50 °C
-50 ... +50 °C
-50 ... +50 °C
-50 ... +50 °C
FC02 - Read input status
Register
Parameter description
Data type
Value
Display
1x0001
Input 1: BIN IN
Bit 0
0 ... 1
On - Off
1x0002
Input 2: BIN IN
Bit 0
0 ... 1
On - Off
FC05 - Write single coil
Register
Parameter description
Data type
Value
Display
0x0001
Zeroing
Bit 0
0 ... 1
On - Off
FC06 - Write single register
Register
Parameter description
Data type
Value
Display
4x0001
Beta value of NTC resistor
16 bit
0 ... 30,000
0 ... 30,000 (standard 4220)
WIKA data sheet SP 69.09 ∙ 04/2015
Page 3 of 4
Menu selection and configuration
Press the SELECT button for 2 seconds to open the menu.
Select the address for Modbus: 1 …
247
Select the baud rate:
9600/19200/38400
Select the parity bit: None/Even/Odd
Select the pressure unit:
Pa/inchWC/mmWC/psi/mbar
Select response times:
1 … 20 seconds
Push the SELECT button:
Exit the menu
Input signal configuration
The input signals can be read over Modbus via DPT MOD RS-485 interface.
Set the jumpers according to the adjacent instructions. Read the value from
the correct register. Both inputs can be configured independently.
Signal
Accuracy
Resolution
0 ... 10 V
< 0.5 %
0.1 %
Pt1000
< 0.5 %
0.1 %
NTC10K
Ni1000/(-LG)
BIN IN (potential-free contact)
< 0.5 %
< 0.5 %
0.1 %
0.1 %
Ordering information
Model / Measuring range / Input signal / Options
© 2015 WIKA Alexander Wiegand SE & Co. KG, all rights reserved.
The specifications given in this document represent the state of engineering at the time of publishing.
We reserve the right to make modifications to the specifications and materials.
WIKA data sheet SP 69.09 ∙ 04/2015
04/2015 EN
Page 4 of 4
WIKA Alexander Wiegand SE & Co. KG
Alexander-Wiegand-Straße 30
63911 Klingenberg/Germany
Tel.
+49 9372 132-0
Fax
+49 9372 132-406
[email protected]
www.wika.de